Intramedullary osteosynthesis nail for healing fractures or bone elongation

ABSTRACT

An intramedullary nail system for use in all human and animal bones for healing fractures or lengthening bones, in particular for use in the femoral region, including an intramedullary nail as the base element, which can optionally be connected at its top and/or bottom end to at least one further implant component via connecting members ( 3, 4, 6, 10 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a system, based on an intramedullary nail, foruse in all human and animal bones for healing fractures or lengtheningbones, in particular for use in the femoral region.

2. Discussion of the Prior Art

Individual solutions are already known for each of the various defectswhich occur. For example, femoral fractures are cared for usingintramedullary nails. Femoral neck nails are used in the event of afemoral neck fracture. These nails are introduced into bores provided inthe intramedullary nail and are guided into the femoral neck. The use ofspecial prostheses is known for the knee and hip regions. In the eventof a total endoprosthesis change, it is possible to utilize a revisionprosthesis.

The abovementioned implants can be used to care for all fractures whichoccur and to bridge bone removals.

However, the drawback has emerged that a patient with a number offractures may have to be provided with various types of implants which,however, are incompatible with one another. In the most serious cases,this may lead to a complete change of implant being required in theevent of the patients clinical picture changing.

A further drawback which has emerged is that the number of parts whichhave to be fitted by the operating surgeon is high.

U.S. Pat. No. 5,620,445 discloses an intramedullary nail which, at itsdistal and proximal ends, can be lengthened by, in each case, oneelement via threaded or conical connections. One of the extensions hasmeans for attaching instruments for positioning and extracting theintramedullary nail. Both extension elements are provided with bores forguiding through-locking screws.

SUMMARY OF THE INVENTION

The invention is based on the object of providing an implant forproviding support during healing of fractures or for bridging bonelosses which solves the problems related above.

The basic concept of the invention resides in the fact that a system isprovided which works on the basis of an intramedullary nail as the baseelement, which can be compatibly connected, optionally via connectingmeans at its top and/or bottom end, to components which can beindividually selected by the operating surgeon for the particularclinical picture of the patient and, if appropriate, can be adapted to achanged clinical picture, without a complete change of implant beingrequired in the second case.

Therefore, working on the basis of the intramedullary nail, it ispossible, if necessary, to extend the basic implant element into theknee or hip region. It has proven to be of great advantage in thisconnection that the nail also allows connection to new components whichare already implanted, so that it is also possible to extend functionseven after the initial operation without having to change the completeimplant.

One advantage is that as a type of modular system, the system can at anytime when necessary have further components added or even removed. Thisresults for one thing, in reduced operation times and advantages for thepatient, since the system can be selected individually according to thepatient's clinical picture, even intraoperatively, and can be adapted inthe event of the clinical picture changing.

For example, it could be necessary to adapt the implant if, in the eventof a tumor being present, parts of the bone have to be removed, but thesize of these parts is only determined during the operation. Dependingon this result, the operating surgeon can then decide on an individualbasis which components are to be attached to the intramedullary nail.

Advantages of the invention also consist in the fact that it is easierand safer to care for fractures by using the inventive system asstandard instruments.

The intramedullary nail is preferably a nail with equidistant lockinggrooves and small target bores over the entire nail length and with twolarge auxiliary bores at the distal and proximal ends. These auxiliarybores allow the intramedullary nail to be aligned precisely in the beampath of an X-ray appliance and allow the nail to be fixed temporarily,in order for the nail to be fixed definitively in the bone by means offixing pins which are introduced into the grooves. Alignment solely bymeans of grooves is only possible with difficulty, since, in contrast toa circular bore, a groove always appears as a groove in the beam path,irrespective of whether or not orthogonality has been established. Inthis context, the term orthogonality is understood to mean that the boreis aligned at right angles to the beam path and thus appears as acomplete circle. The external grooves make the intramedullary nail moreflexible and thus allow forces to be introduced more effectively intothe bone.

The intramedullary nail, as the base element of the system according tothe invention, is matched to the anatomical shape of the bone and mayoptionally be implanted at the proximal or distal end.

The invention provides for connecting means to be provided at both endsof the intramedullary nail, in order in this way to cover the maximumpossible range of indications, i.e. to allow the intramedullary nailbase element to be extended both into the knee region and the hipregion.

These connecting means are preferably designed as internal or externalcones or as screw connections.

However, it is quite possible for the intramedullary nail to be used asa standard locking nail without the connection of other components.

The intramedullary nail can be removed if a rod-like device is screwedor attached to a nail-connecting means, and the nail is then pulled outof the bone after the locking screws have been removed. In doing so, itshould be ensured that a retaining element is present when the rod-likeremoval device is being attached, in order to ensure thereby that thereare no torques transmitted into the bone.

A further aspect of the invention provides a support element which canbe used in particular as a component for the system according to theinvention.

This support element combines a plurality of individual parts whichwould otherwise be required: it is used to hold and fix, for example, afemoral neck nail, which is then driven through the femoral neck intothe femoral head.

The support element has a special implant component for theintramedullary nail of the system as described above as one or moreentry holes and in each case a plurality of exit holes which arearranged at a suitable angle, preferably on the opposite side, withrespect to each entry hole, so that the nail can be guided through thesupport element at an angle which can be selected during introduction.At its bottom end, the support element can be connected via a connectingmeans to the intramedullary nail, preferably via a conical connection.

Preferably, the paths for the femoral neck nail have a profile which ismatched to the nail and is advantageously not circular, in order in thisway to counteract rotation of the femoral neck nail.

Preferably, in each case three exit holes are provided in the supportelement. Their center axes may intersect one another at one point. Theangle ratio of the entry hole to the exit holes may be set in such a waythat the rotational point of the nail which is to be introducedcoincides with the entry hole, although it may also lie at other points.

In addition to the support element, various prosthesis elements areprovided as further components for the system according to theinvention. One example of such elements is the hip-side prosthesisattachment. It is used in combination with the intramedullary nail as,for example, a revision prosthesis.

Similarly, a knee-side prosthesis component may be attached to thebottom end of the nail. This likewise serves, in combination with theintramedullary nail, as, for example, a revision prosthesis. To bridgelarge defects, it is also possible to use both prosthesis componentstogether.

Finally, an intramedullary nail can also be supplemented, for example inthe event of bone loss, by an extension piece of the same type.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is to be described in more detail below with reference toan example. In the drawing:

FIG. 1 shows an intramedullary nail as the basic element of the systemaccording to the invention;

FIG. 2 shows a partial excerpt from FIG. 1, with an internal cone asconnecting means, which may be attached to an extension piece;

FIG. 3 shows a support element with a hip-side head and femoral neckreplacement;

FIG. 4 shows the support element with possible positions of a femoralneck nail which is to be introduced; and

FIG. 5 shows a cross section through a femoral neck nail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a known intramedullary nail 1, as is already used as atibia nail. It is correspondingly larger when used in the femoralregion. The intramedullary nail 1 has external grooves 2 and smaller andlarger bores, some of which are used as auxiliary bores making it easierto align the intramedullary nail in the beam path. The intramedullarynail base element has connecting means 3, 4 and 10 at its top and bottomends. The components can be attached in a form-and/or force-fittingmanner via these connecting means. The connecting means shown here aredesigned as cones or screw threads 20.

In FIG. 2, the connecting means shown is an internal cone 6 which, whensituated on an extension piece 9, can be attached to the external coneshown in FIG. 1.

FIG. 3 shows the support element 5 which can be connected to theintramedullary nail 1 by means of the internal cone 6. The supportelement 5 is provided with a hip-side prosthesis attachment 7. Thesupport element 5 also has further connecting means 11 for connection tofurther components.

The slot 8 is intended to accommodate a locking screw, so that themoments which are introduced into the component can be transmitted tothe bone. This counteracts the possibility of diaphysial dislocation.

FIG. 4 shows the support element 5 and various possibilities for guidingthrough a femoral neck nail. These nails are used to care for fractureswhich extend, for example, through the two osseous prominences(pertrochanteric).

The nail which is to be introduced into the support element 5 projectsthrough the femoral neck into the femoral head and thus forms aprojecting arm which absorbs flexural and rotational forces in thisregion. The support element 5 has one entry hole and a plurality of exitholes 30. The femoral neck nail can thus be held in one of theselectable angular positions.

The cutouts in the support element have the same profile as thecorresponding nail.

FIG. 5 shows a modified known profile of a femoral neck nail.

Thus, while there have been shown and described and pointed outfundamental novel features of the present invention as applied to apreferred embodiment thereof, it will be understood that variousomissions and substitutions and changes in the form and details of thedevices illustrated, and in their operation, may be made by thoseskilled in the art without departing from the spirit of the presentinvention. For example, it is expressly intended that all combinationsof those elements and/or method steps which perform substantially thesame function in substantially the same way to achieve the same resultsare within the scope of the invention. Substitutions of elements fromone described embodiment to another are also fully intended andcontemplated. It is also to be understood that the drawings are notnecessarily drawn to scale but that they are merely conceptual innature. It is the intention, therefore, to be limited only as indicatedby the scope of the claims appended hereto.

What is claimed is:
 1. An intramedullary nail system for healingfractures and lengthening bones, comprising: an intramedullary nailhaving grooves and bores and a proximal end and a distal end; a supportelement connected to at least one of the proximal end and the distal endof the intramedullary nail; and connecting means for connecting thesupport element to the intramedullary nail, the support element havingone of: at least one entry hole and a plurality of exit holes into whicha nail is inserted, the position of the exit holes with respect to theentry hole being such that the nail is insertable at various anglesbetween a longitudinal axis of the nail and the intramedullary nailaxis; a prosthesis attachment; and a nail extension.
 2. Anintramedullary nail system as defined in claim 1, wherein the connectingmeans of the intramedullary nail is a conical surface formed on at leastone end of the nail.
 3. An intramedullary nail system as defined inclaim 2, wherein the connecting means is one of an internal conicalsurface and an external conical surface.
 4. An intramedullary nailsystem as defined in claim 1, wherein the connecting means of theintramedullary nail includes screw threads formed on at least one end ofthe nail.
 5. An intramedullary nail system as defined in claim 1, andfurther comprising further connecting means at an end of the supportelement which is remote from the intramedullary nail for connection tofurther components.
 6. An intramedullary nail system as defined in claim1, wherein the support element has at least three exit holes for thenail.
 7. An intramedullary nail system as defined in claim 1, whereinthe support element includes a hole for introduction of a locking screwfor transmitting moments to the bone.
 8. An intramedullary nail systemas defined in claim 7, wherein the hole for the locking screw is a slot.